Field of the Invention
The present invention relates to a communication apparatus connected to a message communication system in which a plurality of user terminals are interconnected, and messages are exchanged among the plurality of user terminals. The communication apparatus is utilized in the form of such a user terminal.
Recently, there has been developed a message communication system referred to as a so-called chat system in which messages are exchanged between user terminals through a so-called personal computer communication and the like.
FIG. 16 is a conceptual diagram of a message communication system comprising so-called servers and clients.
A plurality of user terminals, or a plurality of client computers 100.sub.-- 1, 100.sub.-- 2, . . . , 100.sub.-- n are connected through a communication network 200 to a host computer 300 which serves as a server, so as to exchange messages among the client computers 100.sub.-- 1, 100.sub.-- 2, . . . , 100.sub.-- n via the host computer 300.
In such a message communication system, there is known a system comprising a common virtual world when the system is viewed as a whole, and the client computers 100.sub.-- 1, 100.sub.-- 2, . . . , 100.sub.-- n having their own symbols referred to as so-called avatars, in which the client computer, who intends to have a message exchange or communication, displays an its display screen the virtual world and avatars or symbols of the clients entered the virtual world just as if a plurality of clients, who are of interest in communication, enter the virtual world and have conversations.
FIG. 17 is an illustration showing exemplarily a display image of a client computer in which the virtual world and symbols as mentioned above are displayed.
In a virtual world display area 111 of a display screen 110 illustrated in FIG. 17, four persons (symbols of four clients) are displayed, and the total five persons including one's own self enter the same scene (virtual space) in the virtual world. A message exchange is performed among these five persons (five client computers). In a message display area 112 of the display screen 110, there are displayed messages exchanged among those five persons entered (five client computers). A click of scroll buttons 113a and 113b with the use of a mouse (not illustrated) makes it possible to scroll the display content in the message display area 112.
In a case where a virtual space is displayed on a display screen, a two-dimensional image, which can be displayed on the display screen, is plotted on the basis of graphic data representative of a three-dimensional figure. In this case, when the two-dimensional image is plotted, there is raised a problem that the virtual space is seen from what viewpoint position and in what eyes direction. According to the explanation made referred to FIG. 17, it is assumed that the images shown in FIG. 17 have been plotted on the basis of a viewpoint element (viewpoint position and eyes direction) of the symbol of one's own self.
FIG. 18 is a schematic diagram showing a functional structure of a client computer adapted to perform a plotting in accordance with the viewpoint element of the symbol of one's own self.
In FIG. 18, an viewpoint element determining means 11 determines a viewpoint element of the symbol of one's own self, that is, viewpoint position and eyes direction, on the basis of a symbol element 1 representative of a coordinate position in a virtual space of the symbol of one's own self (oneself client), a direction which the symbol looks toward, and the like.
A two-dimensional image producing means 12 produces two-dimensional images in case of looking based on the viewpoint element of the symbol of one's own self a virtual space in which the symbol of one's own self is located.
The client computer shown in FIG. 18 is provided with an image display unit 14 having a display screen 14a on which images are displayed. A plotting means 13 plots on the display screen 14a of the image display unit 14 the two-dimensional images produced by the two-dimensional image producing means 12.
In the client computer, thus, the two-dimensional images as shown in FIG. 17 are displayed on the display screen 14a.
In this manner, when the two-dimensional images are displayed on the basis of the viewpoint element of the symbol of one's own self, images looking through eyes of the symbol of one's own self are displayed. Consequently, there will be obtained the reality as if one's own self enters the virtual space. However, the symbol of one's own self is not displayed on the two-dimensional images. According to the recent system, there is provided a delicate constitution such that symbols can make various performances, for example, changing their expression in several ways and raising their hands, by client's operation. However, there is a problem such that even if expression and performance of the symbol of one's own self are changed by the operation of oneself client, one's own self cannot confirm the expression and performance of one's own symbol on the display screen of oneself client.
In order to solve such a problem, it is considered that two-dimensional image based on a viewpoint element different from that of the symbol of one's own self, for example, such a two-dimensional image that one's own self sees from the seats a movie in which one's own self appears on the scene, is produced and displayed on a display screen. In this case, while oneself client can confirm the expression and performance of one's own symbol on the display screen of oneself client, it will be difficult for oneself client to have an impression such that one's own self enters the virtual world.